Abstract: AimTo develop a method for assaying Ginkgo flavones in rat hepatical microsome. Methods Quercetin, isorhamnetin and keampferol were added to microsome incubate and incubated for a given time then extracted with ether-acetone. After evaporated, the residue was reconstituted with 100 μL of phosphate buffer solution (pH 2.0)-tetrahydrofuran-methanol-isopropanol (60∶15∶10∶20). An aliquot of 20 μL was injected into the HPLC system. According to the result of estimate by means of HPLC, the results of metabolism of Ginkgo flavones in different conditions was compared. ResultsThe assay was linear over the rang of 0.2-8 mg·L^-1 for Ginkgo flavones. The limit of quantification was 0.1 mg·L^-1 (N=3). The recoveries of three components of Ginkgo flavones were 99.9%-113.8% for quercetin (RSD<0.8%), 100.8%-117.3% for isorhamnetin (RSD<1.9%) and 100.7%-116.5% for keampferol (RSD<1.03%, N=5). ConclusionThe method is simple, fast and accurate. It can be used for investigation of the metabolism of Ginkgo flavones.